The study, which will be published online Jan. 17 in Clinical Cancer Research, provides evidence that these engineered cells can target many types of pediatric solid tumors, including brain tumors. Better treatments are badly needed for children with these tumors, particularly when traditional therapies fail.

"The prognosis for children with relapsed brain tumors or solid tumors or metastatic disease generally is dismal," said Robbie Majzner, MD, the lead author of the new study and an instructor in pediatrics at Stanford. "We're excited that we have a potential therapeutic representing a completely new modality to treat these children." The study's senior author is Crystal Mackall, MD, the Ernest and Amelia Gallo Family Professor and a professor of pediatrics and of medicine.

Immunotherapies - Adult - Cancers - Childhood - Cancers

Immunotherapies that work well for adult cancers do not always succeed against childhood cancers, Majzner noted. One approach, called checkpoint inhibition, targets gene mutations that are limited in most pediatric cancers.

Another immunotherapy method, using chimeric antigen receptor T cells, or CAR-T cells, is the basis of a treatment for one form of relapsed childhood leukemia. Leukemia is a type of blood cancer. That therapy, tisagenlecleucel (brand name Kymriah), employs synthetic biology to make immune cells that react to a surface marker found on the leukemia cells.

Majzner - Colleagues - CAR-T - Cells - Brain

Majzner and his colleagues decided to try to make CAR-T cells for pediatric brain tumors and solid tumors, including tumors found in bone and muscle. These cancers do not carry the same surface markers as leukemia, so the scientists' first step was to look for another marker that engineered immune cells could target.

"You need high amounts of the target on the tumor cells, and you may need the target to be on every cell in a tumor," Majzner said. The ideal surface marker must not be highly expressed on healthy tissue, to prevent engineered immune cells from...